Applications of microencapsulated essential oils

Abstract

Method for the preparation of microencapsulated essential oils or a formulation thereof for various non-agricultural applications.

Claims

1. A microcapsule comprising an encapsulating amphiphatic shell surrounding a core, said encapsulating amphiphatic shell comprising a multivalent salt form of at least one alkanoic acid, and said core comprising at least one essential oil or derivative thereof, which microcapsules contain the essential oil in an amount of 60-95% of the weight of the microcapsule.

2. The microcapsule of claim 1, wherein said essential oil is selected from the group consisting of anise oil, angelica oil, basil oil, bay oil, bergamot oil, bois de rose oil, camphor oil, cananga oil, cardamom oil, caraway oil, cedar oil, cedarwood oil, Chamaecyparis obtusa oil, chamomile oil, cinnamon oil, citronella oil, clove oil, copaiba balsam oil, cumin oil, clove oil, coriander oil, dill oil, eucalyptus oil, fennel oil, garlic oil, geranium oil, grapefruit oil, ginger oil, guaiac oil, hiba oil, iris oil, Japanese mint oil, jasmine oil, lavender oil, lemon oil, lemongrass oil, linaloe oil, Lindera oil, mandarin oil, mint oil, neroli oil, onion oil, orange oil, oregano oil, palmarosa sofia oil, patchouli oil, parsley oil, pepper oil, peppermint oil, perilla oil, Peru balsam oil, petitgrain oil, pine oil, pine needle oil, rose oil, rosemary oil, sandalwood oil, spearmint oil, star anis oil, sweet orange oil, tangerine oil, tea seed oil, tea tree oil, thyme oil, tolu balsam oil, tuberose oil, turmeric oil, vetivert oil, western mint oil, wintergreen oil and any combination thereof.

3. The microcapsule of claim 1, wherein said core further comprises one or more insect growth regulators (IGR).

4. The microencapsulated essential oil formulation of claim 3, wherein said insect growth regulator (IGR) is selected from the group consisting of pyriproxyphen, azadirachtin and novaluron.

5. The microcapsule of claim 1, wherein the weight of alkanoic acid is about 12% of the weight of the at least one essential oil in the microcapsule.

6. The microcapsule of claim 1, further comprising a nonvolatile oil.

7. The microcapsule of claim 6, wherein said non-volatile oil is selected from the group consisting of pyrethrum oil, sesame oil, cottonseed oil and combinations thereof.

8. A microencapsulated essential oil formulation comprising a plurality of the microcapsules of claim 1, wherein said formulation is solid or liquid.

9. The microencapsulated essential oil formulation of claim 8, wherein the formulation is homogenous or heterogeneous.

10. The microencapsulated essential oil formulation of claim 8, further comprising at least one absorbent is selected from the group consisting of celluloses, starch powders, fumed silicas and any combination thereof.

11. The microencapsulated essential oil formulation of claim 8, further comprising at least one ionic or non-ionic surfactant.

12. The microencapsulated essential oil formulation of claim 8, further comprising at least one additive selected from the group consisting of an active pharmaceutical agent, an antioxidant, a food supplement, an insect growth regulator (IGR), an insecticide, an acaracide, a fungicide, a nematicide, a vitamin, a colorant, an odorant, a flavor, a dispersant, a steric barrier polymer, an emulsifier and any combination thereof.

13. The microencapsulated essential oil formulation of claim 12, wherein said additive is encapsulated or unencapsulated.

14. The microencapsulated essential oil formulation of claim 12, wherein said additive is an insecticide or an insect growth regulator (IGR).

15. The microencapsulated essential oil formulation of claim 14, wherein said insecticide or said insect growth regulator (IGR) is selected from the group consisting of pyriproxyphen, azadirachtin and novaluron.

16. The microencapsulated essential oil formulation of claim 8, further comprising an encapsulated or unencapsulated non-volatile oil.

17. The microencapsulated essential oil formulation of claim 16, wherein said non-volatile oil is selected from the group consisting of pyrethrum oil, sesame oil, cottonseed oil and combinations thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) Summary

(2) There exists the need in the industry for antiseptic pre- and post-milking formulations that are highly effective skin decontaminants for the prevention of mastitis and which at the same time, leave the udder and teat skin in good condition for milking at either low or high frequencies. In addition, such compositions should provide a rapid kill of mastitis-causing microorganisms and be water-soluble, non-toxic and non-sensitizing. Such compositions would benefit dairies that milk at low frequency, and eliminate one of the major impediments to further practical development of high-frequency milking dairies.

(3) It has now been determined, that the formulations comprising encapsulated essential oils prepared by the method of the invention or by interfacial polymerization may be used for combating microbial infections such as mastitis and thus are useful in preventing, controlling and treating the microbial-related disease or disorder.

(4) There is, thus, provided an antimicrobial formulation comprising at least one encapsulated essential oil microcapsule prepared according to the novel method of the invention, or by interfacial polymerization as disclosed hereinabove, wherein said formulations is effective in treating or preventing a disease or disorder associated with at least one microbial pathogen.

(5) The term treating as used herein refers to the application of an amount of the formulation containing volatile essential oils according to the invention which is effective in ameliorating undesired symptoms associated with the disease or disorder, preventing the manifestation of such symptoms before they occur, slowing down the progression of the disease or disorder, slowing down the deterioration of symptoms associated with the disease or disorder, slowing down the irreversible damage caused by the pathogens, lessening the severity or cure of the disease or disorder, ensuing a more rapid recovery, or preventing the disease form occurring or a combination of two or more of the above.

(6) In one embodiment, the microbial pathogen is selected from Escherichia coli, Staphylococcus Aureus, Micrococcus CNS, Streptococcus Dysgalactiae, Areanobacterium Pyrogenes, and Pseudomonas Aeruginos.

(7) In another embodiment, said antimicrobial formulation is for treating or preventing mastitis in milking animals and humans.

(8) In another embodiment, said antimicrobial formulation is an antiseptic formulation.

(9) Also provided is a method for modulating mastitis in milking animals, said method comprising applying onto said animal's teat an antimicrobial essential oil formulation, said formulation being optionally capable of forming a barrier layer, thereby substantially preventing the entry of microbes into the udder.

(10) The term modulating as used herein refers to the application of an amount of the formulation containing volatile essential oils according to the invention which is effective in ameliorating undesired symptoms associated with mastitis, preventing the manifestation of such symptoms before they occur, slowing down the progression of mastitis, slowing down the deterioration of symptoms associated with mastitis, slowing down the irreversible damage caused by the pathogens, lessening the severity or cure mastitis, improving milking or more rapid recovery, or preventing the disease form occurring or a combination of two or more of the above.

(11) Also provided is a method for reducing microbial population on a surface or an object, said method comprising applying onto said surface or object an antimicrobial essential oil formulation, optionally being capable of forming an antimicrobial barrier layer.

(12) In one embodiment, said surface or object is a milking animal's teat.

(13) The term milking animal refers to an animal that is considered a dairy animal. Such animals may be cows, goats, camels, alpacas, etc. However, such formulations may be effective also in the treatment of mastitis in milking animals which milk is typically not part of the human diet. The term also refers to humans.

(14) The formulations employed may be heterogeneous or homogenous. Additionally, the microencapsulated essential oils may be presented to the target along with a high boiling (active or non-active) vehicle, as disclosed by the inventors of the present invention in U.S. application Ser. No. 11/040,102, incorporated herein in its entirety.

(15) In another embodiment, said formulation comprises at least one encapsulated antimicrobial essential oil and at least one non-encapsulated essential oil, acting as the carrier. Preferably, said antimicrobial essential oil is one or more of oregano oil, basil oil, rosemarin oil, eucalyptus oil, tea tree oil, or thyme oil.

(16) Other essential oils, which may be encapsulated, are those obtainable from the Lamiaceae, Labiatae, or Verbenaceae families.

(17) The formulation which is capable of forming a barrier layer may further comprise a polymer which upon application to the skin of the animal dries to form said barrier. Alternatively, the formulation may comprise at least one monomer which polymerizes upon drying or in the presence of an initiator to form the polymer barrier.

(18) In one embodiment, the antimicrobial barrier formed after application of the formulation of the invention is based on a polymer or a monomer being contained within the essential oil formulation. In another embodiment, the polymer or monomer is not contained within the formulation but is applied onto the skin following application of the essential oil formulation, before application or in a mixture prepared immediately before application.

(19) The essential oil formulation used for the modulation of the microbial-related disease such as mastitis or for reducing microbial population, may further comprise other antibacterial agents commonly used to control or treat the disease, e.g., mastitis. Such combination may result in a more effective antimicrobial activity which may also exhibit a prolonged effect or a broader effect on a greater variety of microbes. Additionally, such combination may significantly reduce the effective concentration of the said antibacterial formulation. Thus, such formulations may be used to modulate both the contagious and environmental forms of mastitis.

(20) Without being limited thereto, the additional antimicrobial agent may be selected from stabilized chlorine such as chlorine dioxide, chlorhexidine salts, chlorine release compounds such as alkali hypochlorites, oxidizing compounds such as hydrogen peroxide and peracids; protonated carboxylic acids (i.e. fatty acids) such as heptanoic, octanoic, nonanoic, decanoic, undecanoic; acid anionics such as alkylaryl sulfonic acids; quaternary ammonium salts, and iodine.

(21) The formulations of this aspect may be applied to the teats of the milking animals by any known method such as spraying, brushing, swabbing or foaming onto the teats, and at any time during the milking period. The formulations may also be applied by dipping (so-called teat-dip application) the teat into a reservoir or receptacle containing the formulation of the invention.

(22) After application, the teats that have been covered by the formulation are allowed to dry, at which point the antimicrobial barrier and prophylactic shield form.

(23) In one embodiment, the formulation may be sprayed on the animal's udder immediately after milking when the teat is most susceptible to infection and may be removed from the animal's udder prior to the next milking. Such post-milking application may prevent entry of pathogens into the teat immediately after milking, as the teat-end sphincter muscle (responsible for closing the teat-end) remains open for approximately 30 minutes after milking.

(24) In another embodiment, the anti mastitis formulation may be applied at the start of and during the dry period when milking in not carried. It could be applied periodically to the udder throughout the dry period to prevent and control mastitis. An essential part of a mastitis control program is the dry cow therapy. Dry cow therapy is treatment of a cow during the approximately four to ten-week period immediately preceding the delivery of a calf. This period is also known as the non-lactating period. Although during this period the mammal is not exposed to potential contamination form milking machines, forty to fifty percent of teat infections occur during this period. This high rate of infection occurs since a mammal's immune response is diminished during the dry period. Additionally, the teat is distended during the dry period allowing more facile microbial penetration into the mammary gland and without the flushing lactation, the likelihood of infection increases. Thus, treating a dairy animal during its dry period should also minimize the rate of infection.

Example 1

(25) A solution of 35 g tolylene diisocyanate (TDI) mixed into 250 g of an essential oil (Table 1) was added into 500 g water containing 5 g polyvinyl alcohol (PVA) using a high sheer mixer. To this were added 120 ml of water with 55.6 g polyethylene glycol (PEG) 4000. The mixing was continued for two hours at room temperature. The emulsion which resulted was treated with 12 g Guar gum and 4 g of a Nefocide. To break up the hydrogel consistency of the emulsion, 10 g of 1% sodium dodecyl sulfate (SDS) were added.

(26) The formulation was next tested on a variety of microorganisms in order to evaluate its antimicrobial efficacy, particularly in treating mastitis.

(27) Generally, the formulation was found to be an efficient antimicrobial formulation, having efficacy against all the pathogens tested.

Example 2

(28) 10 g of an essential oil with 12 g stearic acid dissolved therein were added to a rapidly stirring (high speed shear stirrer) solution of 250 ml H.sub.2O with 2.5 g polyvinyl alcohol (PVA). To this, a solution of 22.8 g hexahydrate CaCl.sub.2 in 20 ml H.sub.2O was added and stirred for two hours. Next, 1.5 g methyl paraben, 8 ml Latron B 1956 and 3 g Guar gum were added with continual stirring for another 2 hours. Microcapsules containing other essential oils were prepared similarly: 1Tea tree oil encapsulated in Lauric acid by CaCl.sub.2; 2Thyme oil encapsulated in stearic acid by CaCl.sub.2; 3Eucalyptus oils encapsulated in stearic acid by CaCl.sub.2 with free Pyrethrum and Sesame oil; 4Oregano oil encapsulated in decanoic acid by CaCl.sub.2 with free Pyrethrum and Sesame oil; 5Tea tree oil encapsulated in decanoic acid by FeCl.sub.2; 6Citronella oil encapsulated in Lauric acid by MgCl.sub.2 with free Pyrethrum and Sesame oil; 7Tea tree oil encapsulated in decanoic acid by MgCl.sub.2.
In-Vitro Tests:

(29) Samples of the following pathogenic bacteria received from the Israeli Dairy Board (Production and Marketing) were used to test the efficacy of the above formulation:

(30) a) Escherichia coli,

(31) b) Staphylococcus Aureus,

(32) c) Micrococcus CNS,

(33) d) Streptococcus Dysgalactiae,

(34) e) Areanobacterium Pyrogenes, and

(35) g) Pseudomonas Aeruginos.

(36) Each of the different bacteria was grown on TSBA and sheep's blood plates at 37 C. for 18 hours. Arcanobacterium Pyrogenes was grown at 30 C. for 42 hours. Next, the bacteria were washed from the plates with 0.9N sterile saline and suspended in sterile saline. The concentration of the bacterial suspension was adjusted to approximately 510.sup.8 CFU/ml.

(37) To the suspension, essential oil formulations containing oregano oil, tea tree oil, or thyme oil were applied. Varying concentrations of the essential oil formulations were used, ranging from 0.01% to 1%. Common volume of inoculum bacteria with oil formulation was 5 ml.

(38) After vortexing the mixture of the inoculum and essential oil formulation for 10 minutes, the mixture was filtered through a sterile glass microfilter (GF/C 1.2 microns from Whatman filter company) using a vacuum pump.

(39) The liquid filtrate was diluted and transferred to a TSBA and sheep's blood plate. The plate was incubated at the optimal temperature for 18-42 hours; thereafter the colony of bacterial on each plate was counted.

(40) The results are summarized in Tables 1 and 2 below:

(41) TABLE-US-00001 TABLE 1 Summary of antibacterial efficacy of different formulations of essential oils encapsulated according to the procedure of Example 1. Tea tree Thyme Oregano Formulation MIC Concentration (%) Bacteria Type/CFU (Bacterial counts per 1 ml) Escherichia Coli/2 10.sup.8 0.05 0.02 Staphylococcus 0.2 0.1 aureus/4 10.sup.8 Pseudomonas 0.2 0.02 aeruginosa/8 10.sup.8 Micrococcus CNS/5 10.sup.9 0.4 0.4 0.2 Streptococcus 0.08 0.08 0.2 Dysgalactiae/2.5 10.sup.8 Areanobacterium 0.08 0.08 0.08 Pyrogenes Nature of encapsulation Polymeric Polymeric Polymeric envelope envelope envelope Polyurethane Polyurethane Polyurethane

(42) TABLE-US-00002 TABLE 2 Summary of antibacterial efficacy of different formulations of essential oils encapsulated according to the method of Example 2. Tea tree Tea Tree Formulation MIC Concentration (%) Bacteria Type/CFU (Bacterial counts per 1 ml) Escherichia Coli/2 10.sup.8 0.1 1.0 Staphylococcus >0.6 >0.8 aureus/4 10.sup.8 Pseudomonas 0.8 1.0 aeruginosa/8 10.sup.8 Nature of encapsulation Stearic with CaCl.sub.2 Lauric acid with CaCl.sub.2

Example 3

(43) Essential oils such as tee tree oil, eucalyptus oil, oregano oil, essential oils obtained from thyme, essential oils from the herbs of the genus origanum and other essential oils of plant species that of the Lamiaceae, Labiatae, and Verbenaceae families were also encapsulated according to the method of Example 2.

(44) These essential oils were also encapsulated by interfacial polymerization as disclosed in Example 1. Mixtures of microcapsules containing polyurethane microcapsules and polyurea microcapsules, each with a different release profile to give a wider range of release profiles for the formulation were also prepared.

(45) Repellency and Extermination of Insects

(46) Background

(47) Unlike insecticides which may exert their effect only after the insects have settled on the target, thereafter stinging with the possibly resulting immediate or delayed infection, insect repellants prevent harmful insects from flying in or touching and from stinging and sucking on surfaces attractive to them, as for instance the skin of animals and humans. In many areas, the driving off of stinging, blood-sucking and other bothersome insects is an urgent need, because they may in part also transmit diseases. Active substances for driving off such insects, therefore, have an important sanitary, hygienic and cosmetic function to fulfill.

(48) Insect repellants are widely used throughout the United States and throughout the world. In some regions, the use of insect repellants is critical to avoiding or reducing the occurrence of disease carried by insects. For example the Centers for Disease Control (CDC) receives nearly 101,000 reports of Lyme disease (transmitted by deer ticks) and 1,000 reports of encephalitis (transmitted by mosquitoes) annually.

(49) Numerous effective repellants are known in the art. One of these, N,N-diethyl-m-toluamide (DEET) has been shown to be excellently effective as a mosquito repellant and is currently considered one of the most commonly used. DEET was designed to be applicable to the skin of subjects, and to repel rather than kill insects. A number of compositions containing this material are commercially available for use on humans and animals, for instance in the form of creams or aerosol compositions.

(50) Concerns have recently been raised as to the potential toxicity of long-term use of DEET and other available pest repellants to children. At present, it is forbidden to use DEET on children below the age of seven. Recently the US Environmental Protection Agency (EPA) determined that it would no longer allow child safety claims on labels for DEET-containing products. In addition, although DEET is effective as a repellant, it has the dual disadvantage that it must be used in relatively high concentrations and, more importantly, it is not effective for affording continuous protection against pests for more than about six hours.

(51) Numerous encapsulated insect repellents in time control release agents have been reported. Examples of such repellent systems are disclosed in U.S. Pat. No. 4,548,764 to Munteanu et al., and U.S. Pat. No. 5,069,231 to Rutherford. Such repellent encapsulation systems have very limited effectiveness overtime and are typically effective for less than one week. Highly volatile materials such as esters, ethers, and aldehydes are commonly found in available compositions which make these compositions inherently unstable and therefore require the presence of chemical stabilizers.

(52) Another available repellant for repelling small blood-feeding pests from the skin, hair, or fur of a mammal is cyano(3-phenoxyphenyl)methyl-4-chloro-alpha-(1-methylethyl)-benzeneacetate. The active compound is conveniently formulated into compositions which are adapted to topical application to the skin, hair, or fur of a mammal (see for example U.S. Pat. No. 4,547,360).

(53) Essential oils have also been used in repelling insects. Lavender oil, for example, was used to protect children from head lice infestation. Recently piperonal (1,3-benzodioxol-5-carboxaldehyde) was introduced as a repellent to the market. Citronella candles used to repel insects have also been manufactured, despite the showing that citronella oil is not a very effective insect repellent even when released into the air from a candle. Even commercially available topical compositions containing citronella oil are not very effective, probably due to the fact that they work for a very short period of time, i.e., 10-20 minutes or less if the subject perspires, and due to the need to cover the whole body if a complete repelling effect is sought.

(54) The use of essential oil based formulations in agriculture has also been reported. PCT Publication No. WO 04/098767 to the inventors of the present invention discloses microcapsules of essential oils which may be used, among other applications, as pesticides, insect repellents, and as antiviral or antifungal agents. When the microcapsules are applied to given substrates, the essential oil contained therein is released at a constant rate over a period of time. The efficacy of such microcapsules depends on the potency of the encapsulated material and parameters relating to the microcapsules themselves, i.e., size, thickness of the encapsulating membrane, ability to sustain release of the essential oil contained therein, etc., and not on the aqueous medium which carries them to the target environment which dries immediately thereafter.

(55) U.S. application Ser. No. 11/040,102 to the inventors of the present invention discloses encapsulated essential oil formulations which comprise at least one encapsulated volatile essential oil and a non-volatile vehicle in which said at least one volatile essential oil is carried. Such formulation is used for the management of pest populations in agricultural environments.

(56) Summary

(57) It has now been found that the essential oil formulations such as those manufactured in accordance with the methods of U.S. application Ser. No. 11/040,102, or the method of the present invention, may be used for repelling or exterminating insects from the skins of animals or humans or from surfaces and objects on which they may land or to which they may be attracted. Such insects are capable of causing annoyance or injury to animals or humans and may for example be mosquitoes, ticks, flies, ants and cockroaches. It has been further discovered that such a formulation may be applied directly to the skin of such animals or humans or to in-door or out-door surfaces which may be in contact or in close proximity to animals or humans.

(58) The formulations of U.S. application Ser. No. 11/040,102, for example, which comprise encapsulated volatile essential oils (e.g., citronella) and non-volatile essential oils as vehicles (e.g., pyrethrum) and which may further comprise active agents such as the insect growth regulator, Novaluron, (contained with the encapsulated essential oil, in the vehicle, or both) have demonstrated their efficacy in repelling or exterminating insects from wet or humid environments such as natural or artificial water reservoirs such as fish tanks, lakes, aquariums, drinking water reservoirs, and other aquacultures.

(59) It has also been determined that the repellent/exterminating formulations may be used to achieve one or more of the following advantages over an existing insect repellent available for similar purposes:

(60) 1. They may be more effective then those commercially available for application onto human skin;

(61) 2. They significantly reduce insect population within the treated area, thus eliminating or significantly reducing the use of skin contact formulations;

(62) 3. They more effectively reduce the spread of diseases or nuisances by mosquitoes and other insects;

(63) 4. They may be used in conjunction with skin formulations in heavy mosquito or insect infestations for a synergistic affect;

(64) 5. They may be used to reduce pest population in animal areas such as kennels, barns and circuses without application to individual animals; and

(65) 6. They may be applied in the vicinity of children, thus obviating the use of direct contact and ensue of side effects to which children are more prone to than adults.

(66) Thus, in another aspect of the present invention there is provided a repellant or insecticidal formulation for reducing the population of insects in a treated non-agricultural environment, said formulation comprising at least one encapsulated volatile essential oil and a non-volatile vehicle in which said at least one volatile essential oil is carried. The non-volatile vehicle may be a solid or a liquid vehicle.

(67) In one embodiment, the formulation of encapsulated essential oil is prepared according to the method of the invention. In another embodiment, the formulation of encapsulated essential oil is prepared by interfacial polymerization.

(68) In another embodiment, said insect is capable of causing annoyance or injury to animals or humans. Such insects may be, without being limited thereto, selected from mosquitoes, ticks, flies, ants and cockroaches.

(69) In another embodiment said non-volatile vehicle is selected from the group of non-volatile essential oils, non-volatile botanical oils or any combination thereof.

(70) When the formulation is made suitable for direct application onto the skin of animals or humans it may further comprise at least one pharmaceutical or cosmetic agent which may provide additional benefit when applied to the skin (e.g. menthol, vanillin).

(71) For human or animal use, the essential oils may be selected from: peppermint oil, clove oil, eucalyptus oil and lavender oil; anise oil, angelica oil, iris oil, fennel oil, orange oil, cananga oil, caraway oil, cardamom oil, guaiacwood oil, cumin oil, Lindera oil, cinnamon oil, geranium oil, copaiba balsam oil, coriander oil, perilla oil, cedarwood oil, citronella oil, jasmine oil, palmarosa sofia oil, cedar oil, spearmint oil, Western mint oil, star anis oil, tuberose oil, clove oil, Neroli oil, wintergreen oil, tolu balsam oil, patchouli oil, rose oil, palmarosa oil, Chamaecyparis obtusa oil, Hiba oil, sandalwood oil, petitgrain oil, bay oil, vetivert oil, bergamot oil, Peru balsam oil, bois de rose oil, camphor oil, mandarin oil, eucalyptus oil, lime oil, lavender oil, linaloe oil, lemongrass oil, lemon oil, rosemary oil, and Japanese mint oil.

(72) Essential oils which may be encapsulated in formulations directed at repelling insects from human or animal skin may be selected from almond bitter oil, anise oil, basil oil, bay oil, caraway oil, cardamom oil, cedar oil, celery oil, chamomile oil, cinnamon oil, citronella oil, clove oil, coriander oil, cumin oil, dill oil, eucalyptus oil, fennel oil, ginger oil, grapefruit oil, lemon oil, lime oil, mint oil, parsley oil, peppermint oil, pepper oil, rose oil, spearmint oil (menthol), sweet orange oil, thyme oil, turmeric oil, and oil of wintergreen.

(73) Examples of active ingredients in essential oils are: citronellal, methyl salicylate, ethyl salicylate, propyl salicylate, citronellol, safrole, and limonene, Organo, citronella and lavender, geranium oil, rosemary oil and peppermint oil spearmint oil, pine needle oil and eucalyptus oil. Less suitable, but still effective are lemon oil, grapefruit oil, lavandin oil, cinnamon oil, clove oil, thyme oil, wintergreen oil, cedar oil, lemon grass oil, mandarin oil, tangerine oil, orange oil, citrus oil, lime oil, coriander oil, pomegranate oil, walnut oil, peanut oil, corn oil, canola oil, sunflower oil, sesame oil, linseed oil, safflower oil and olive oil.

(74) Essential oils which may be used in formulations for use as larvicide and insecticide and which are suitable to human and animal use may be selected from pine pyrethrum, tea tree, thyme and essential oils that come from these familiesalpha-terpineol, amyl cinnamic aldehyde, amyl salicylate, anisic aldehyde, benzyl alcohol, benzyl acetate, cinnamaldehyde, cinnamic alcohol, carvacrol, carveol, citral, citronellal, citronellol, dimethyl salicylate, eucalyptol (cineole), eugenol, iso-eugenol, galaxolide, geraniol, guaiacol, ionone, d-limonene, menthol, methyl anthranilate, methyl ionone, methyl salicylate, alpha-phellandrene, pennyroyal oil, perillaldehyde, 1- or 2-phenyl ethyl alcohol, 1- or 2-phenyl ethyl propionate, piperonal, piperonyl acetate, piperonyl alcohol, D-pulegone, terpinen-4-ol, terpinyl acetate, 4-tert butylcyclohexyl acetate, thyme oil (white and red), thymol, trans-anethole, vanillin, ethyl vanillin, and the like.

(75) Also useful are rosemary oil and/or wintergreen oil that can be used with plant essential oils such as thyme oil, eugenol and 2-phenethyl propionate, carvacrol and beta-thujaplicine derived from Thujopsis dolabrata var hondai sawdust.

(76) Additional agents may be selected from adjuvants, antioxidants, UV absorbers, surfactants, water soluble polymers, and non-water soluble polymers, solvents (e.g., alcohols) and the like.

(77) The applicability of any one certain formulation as a repellent or an insecticide depends on the essential oil or essential oil combination used. One essential oil combination may be useful for only repelling the insects while the other may be efficient in exterminating them. The concentration of the essential oil formulation used may also have an effect on the repellency or extermination capabilities of the formulation.

(78) The term to repel or any lingual variation thereof refers to the act of driving the insects off without ensuing their death. The term to exterminate or any lingual variation thereof refers to the act of killing a whole population of insects or any part thereof. The term insect refers to mosquitoes, ticks, flies, ants and cockroaches and other insects, nematodes, that cause annoyance or injurious to animals or humans.

(79) The term mosquito as used herein concerns any type of mosquito, e.g., Anopheles, Aedes, and Culex, including but not limited to Tiger mosquitoes, Aedes aborigines, Aedes Aegypti, Aedes, albopictus, Aedes cantator, Aedes sierrensis, Aedes sollicitans, Aedes squamiger, Aedes sticticus, Aedes vexans, Anopheles quadrimaculatus, Culex pipiens, and Culex quinquefaxciatus.

(80) The term tick as used herein includes any type of tick, including but not limited to, deer ticks, the American dog tick (Dermacentor variabilis), Ornithodoros parkeri, O. moubata, and Dermacentor andersoni. The term cockroach as used herein refers to any type of cockroach, including but not limited to the American cockroach (Periplaneta americana), German cockroach (Blattella germanica), oriental cockroach (Blatta orientalis), wood cockroach (Parcoblatta pennsylvanica), brownbanded cockroach (Supella longipalpa), and smokybrown cockroach (Periplaneta fuliginosa).

(81) By repelling or exterminating the population of insects capable of inflicting damage to the target environment, the formulations may also assist in reducing damage caused by viruses, by limiting viral transmission by insect vectors.

(82) The formulations may be prepared in various forms depending on the application, the environment treated, the concentration of the formulation applied and the degree of coverage (e.g. application to the whole skin or to the skin covering a specific organ). Such preparation forms may be, without being limited thereto, selected from emulsified concentrate, wettable powder, granular wettable powder, flowable preparation, suspension, granule, dust, fumigant, solution, sprayable preparation and aqueous solution.

(83) The present invention further provides a method for repelling or exterminating an insect population capable of causing annoyance or injury to animals or humans, said method comprising applying to a non-agricultural environment or to an insect population in said environment a formulation comprising at least one encapsulated volatile essential oil and a non-volatile vehicle in which said at least one volatile essential oil is carried.

(84) In one embodiment, the method involves direct application of the formulation onto the skin of animals or humans.

(85) In another embodiment, the method involves application of the formulation onto surfaces such as floors, walls, ceilings, furniture, nets, screens, lawns, clothing, car seats, surfaces in animal husbandries, and aquacultures.

(86) It has also been found in the course of the investigation leading to the invention of the present application, that the non-volatile vehicle enhances the repelling effect exerted by the volatile essential oil, and that the effect exerted by the non-volatile vehicle is enhanced by the volatile essential oil. Thus, the present invention further provides repellent formulations comprising each an effective amount of the formulation of the present invention.

(87) In another embodiment, the formulation may also comprise in addition to the essential oil repellants at least one additive selected from insect growth regulators (IGR), insecticides, acaracides, fungicides, nematicides, and/or ectoparasiticides, either within the microcapsule or as part of the vehicle. Preferably, said formulation may contain at least one insecticide which are soluble in either said at least one encapsulated essential oil or in the non-volatile vehicle. Such insecticides may for example be carbamates, ureas, triazines, triazoles, uracils, organophosphates, morpholines, dinitroanilines, acylalaninies, pyrethroids, and organochlorines. Specific examples are carbofuran, azinphos-methyl, sulfentrazone, carfentrazone-ethyl, cypermethrin, cyromazine, beta-cyfluthrin, endosulfan, phosmet, chlorobromuron, chloroxuron, chlorotoluron, fluometuron, metobromuron, thiazafluron, teflubenzuron, hexaflumuron, diflubenzuron, flufenoxuron, lufenuron, chlorfluazuron, novaluron. dimethachlor, metolachlor, pretilachlor, 2-chloro-n-(1-methyl-2-methoxyethyl)-acet-2,6-xylidide, alachlor, butachlor, propachlor, dimethenamid, bifenox, 4-(4-pentyn-1-yloxy)diphenylether, acifluorfen, oxyfluorfen, fluoroglycofen-ethyl, fomesafen, cis,trans-(+)-2-ethyl-5-(4-phenoxyphenoxymethyl)-1,3-dioxolane, fluazifop-butyl, haloxyfop-methyl, haloxyfop-(2-ethoxyethyl), fluorotopic, fenoxapropethyl, quizalofop-ethyl, propaquizafop, diclofop-methyl, butralin, ethalfluralin, fluchloralin, isopropalin, pendimethalin, profluralin, trifluralin. aclalanines furalaxyl, metalaxyl, benzoylprop ethyl, flamprop methyl, difenoconazole, etaconazol, propiconazole, 1,2-(2,4-dichlorophenyl)-pent-1-yl-1h-1,2,4-triazole, triadimefon, dioxacarb, furathiocarb, aldicarb, benomyl, 2-sec-butylphenylmethylcarbamate, etiofencarb, fenoxycarb, isoprocarb, propoxur, carbetamid, butylate, di-allat, eptc, molinate, thiobencarb, tri-allate, vemolate, piperophos, anilofos, butamifos, azamethiphos, chlorfenvinphos, dichlorvos, diazinon, methidathion, azinphos ethyl, azinphos methyl, chlorpyrifos, chlorthiofos, crotoxyphos, cyanophos, demeton, dialifos, dimethoate, disulfoton, etrimfos, famphur, flusulfothion, fluthion, fonofos, formothion, heptenophos, isofenphos, isoxathion, malathion, mephospholan, mevinphos, naled, oxydemeton methyl, oxydeprofos, parathion, phoxim, pyrimiphos methyl, profenofos, propaphos, propetamphos, prothiophos, quinalphos, sulprofos, phemephos, terbufos, triazophos, trichloronate, fenamipos, isazophos, s-benzyl-o,o-diisopropylphosphorothioate, edinphos, and pyrazophos.

(88) In another embodiment, the formulation of the present invention may be used against viral transmitting insects capable of acting as viral vectors for infection. The term viral vector refers to any such insect as defined and exemplified herein which is capable of carrying and transmitting a plant virus disease-causing, organism.

(89) In another aspect of the present invention, there is provided a method for managing insect population, said method comprising applying to the target environment or to said insect population or to the loci thereof, a microencapsulated essential oil formulation as disclosed herein.

(90) The term non-agricultural target environment as used herein generally refers to an environment which is different from agricultural or horticultural environments. The term, however, refers to in-door or out-doors environments from which the repelling or exterminating of insects is desired. Such may be rooms in a home, work offices, building interiors, gardens, schools, nurseries, public entertainment areas, sport stadiums, transportation areas like subway stations, airport terminals, boats yachts, cars, buses, trains and the like. Surfaces that may be sprayed are floors, walls, ceilings furniture, nets, screens, lawns, etc.

(91) Since most of the insects capable of causing annoyance or injury to animals or humans find their habitat next to or in wet environments such as ponds, there exists the need to exterminate existing insect population from such wet environments, i.e., aquaculture, or to repel them therefrom.

(92) In fact, it has been found that the formulations of the invention may be applied to various water reservoirs thereby achieving either extermination of existing populations of such insects or repelling opportunistic insects from the target water reservoirs. This avoids the need of using toxic and long-surviving chemicals which may create an environmental hazard to both the environment and to humans and animals using such water reservoirs on a recreational or as daily basis.

(93) The term water reservoirs or wet environment refers herein to, without being limited thereto, water systems, cooling systems, swimming pools, natural and artificial water reservoirs, fisheries, water tanks, aquariums, irrigation systems and any other volume of water.

(94) In one embodiment, the formulation is added in a dry form to the water reservoir in an amount sufficient to manage the insect population. In another embodiment, the dry composition is added to a water reservoir after being dissolved in an appropriate vehicle.

(95) The formulations used in eradicating pests from water reservoirs may also be useful to control microorganisms and prevent root intrusion into the water source, particularly irrigation tubes.

(96) Drip irrigation, from both above the surface and also from below, by a technique referred to as subsurface or low volume irrigation, is the process of delivering water and nutrients directly to the plant's root zone. Such water delivery affords exact irrigation control and efficient use of limited water resources. The ease by which such irrigation systems have been installed and the relatively low cost of installation has made subsurface irrigation the solution of choice of both private and municipal consumers for watering gardens and parks.

(97) With the use of reclaimed water for watering of plants a properly engineered and managed subsurface drip irrigation system offers many advantages over conventional watering methods as such subsurface irrigation minimizes health risks associated with exposure to reclaimed water by distributing the water below ground.

(98) One of the primary challenges of utilizing subsurface drip irrigation for long-term applications has been the potential for internal plugging of the irrigation systems and external root intrusion into the drip tubing. Numerous solutions have been proposed as solutions. For example, some use trifluralin to prevent root intrusion into the emitters, while others incorporate a root intrusion barrier directly into the tubing material itself.

(99) While root intrusion into the drip lines and internal clogging from the buildup of sediment, suspended solids, algae and bacterial slime have been diminished greatly by better pretreatment, filtration disinfections, and new tubing and emitter designs, there exists the need for a unified method which would prevent both the intrusion of opportunistic roots and the build up of sediment due to growth of fungi and bacteria.

(100) One of the biggest problems in aquaculture production and managing is the bacteria and fungi in the water which quickly multiply and kill fish and shrimps within a matter of hours or days. Application of the formulations disclosed herein to such aquacultures helps in controlling such fungi and bacteria and thus assists in maintaining a live and health stock.

(101) Bacterial and fungal infestations may be controlled as discussed hereinbefore. Nematodes may also be controlled by applying to the soil an essential oil formulation of the invention which comprises a natural essential oil, which controls nematodes and their eggs.

(102) It has now been discovered that incorporation of a formulation comprising encapsulated essential oils also into the water flow of subsurface irrigation systems allows a long-term control of microorganisms and prevents root intrusion into the tubing.

(103) Thus, the present invention also provides a formulation comprising at least one essential oil which may be chosen from those with antimicrobial and/or fungicidal properties as disclosed herein for use in the control of microorganisms and prevention of root intrusion into irrigation tubings. Examples of such essential oils are tea tree oil, thyme oil, clove oil, eucalyptus oil, oregano oil, citronella oil, basil oil, oil of fennel and oil of anise.

(104) In one embodiment, these essential oils may be used with mixtures of synthetic herbicides for root control. In another embodiment, essential oils with herbicidal properties used. These essential oils having herbicidal properties or synthetic herbicides may be encapsulated together or in different microcapsules.

(105) The essential oils having herbicidal properties are those which comprise a monocyclic, carbocyclic ring structure having six-members and substituted by at least one oxygenated or hydroxyl functional moiety. Examples of plant essential oils encompassed within this definition, include, but are not limited to, members selected from the group consisting of aldehyde C16 (pure), amyl cinnamic aldehyde, amyl salicylate, anisic aldehyde, benzyl alcohol, benzyl acetate, cinnamaldehyde, cinnamic alcohol, alpha-terpineol, carvacrol, carveol, citral, citronellal, citronellol, p-cymene, diethyl phthalate, dimethyl salicylate, dipropylene glycol, eucalyptol (cineole), eugenol, iso-eugenol, galaxolide, geraniol, guaiacol, ionone, d-limonene, menthol, methyl anthranilate, methyl ionone, methyl salicylate, .alpha.-phellandrene, pennyroyal oil, perillaldehyde, 1- or 2-phenyl ethyl alcohol, 1- or 2-phenyl ethyl propionate, piperonal, piperonyl acetate, piperonyl alcohol, D-pulegone, terpinen-4-ol, terpinyl acetate, 4-tert butylcyclohexyl acetate, thyme oil, thymol, metabolites of trans-anethole, vanillin, ethyl vanillin, and the like.

(106) These essential oils may also be used as carriers for encapsulated essential oils with antimicrobial and fungicidal activity.

(107) The essential oils either for antimicrobial or/and fungicidal and/or herbicidal may be encapsulated together in the same microcapsules or made in separate microcapsules and then mixed.

(108) The formulation of the present invention may be presented, stored, packed or applied as a single formulation, wherein the encapsulated volatile essential oil is pre-mixed with the non-volatile vehicle, or as a two-component formulation, which comprises the encapsulated volatile essential oil as one component, for example in a separate container or applied separately, and the non-volatile vehicle as a second component.

(109) Thus, there is provided a method for managing insect population, said method comprising: applying to the target a microcapsule formulation comprising at least one volatile essential oil, and applying to the target environment a second formulation comprising a non-volatile agent.

(110) The application of the second formulation may be done immediately after the application of the first formulation, or at any time thereafter. A person skilled in the art would be able to decide which of the two methods of managing insect populations disclosed herein is more suitable for the specific case.

(111) The formulation disclosed herein may be delivered to the target by any method known to a person skilled in the art. Such methods may include for example: (a) manual or mechanical application of the formulation to a given surface by, for example, applying a liquid preparation either diluted or undiluted with water to said surface; (b) applying a granular agent such as dust or a wettable powder to the surface (c) ground or aerial spraying of a liquid formulation to the many gardens within a neighborhood or to specifically selected areas; (d) burying the formulation in the topsoil of a garden, etc.

A) Formulations Used for Repelling Mosquitoes

(112) The following formulations were used for repelling mosquitoes from a variety of surfaces and indoor or outdoor locations:

(113) Formulation 1: Citronella oil, lavender oil, geranium oil in a ratio of 1:1:1 dissolved in almond oil forming a 24% solution of the oils (purchased under the brand name Di-Tush, Tamar Ltd., Israel) were microencapsulated in a polyurethane envelope by the procedure described in Example 1 below.

(114) Formulation 2: Encapsulated Citronella oil and non-encapsulated pyrethrum and sesame oil.

(115) Formulation 3: Encapsulated Citronella oil with Novaluron and non-encapsulated pyrethrum and sesame oil.

(116) Formulation 4: Encapsulated Citronella oil with Novaluron and non-encapsulated pyrethrum and sesame oil and 20 mg Novaluron.

(117) Formulation 5: Encapsulated Citronella oil with Novaluron and non-encapsulated pyrethrum and sesame oil and 10 mg Novaluron.

(118) Formulation 6: Encapsulated Citronella oil with Novaluron and non-encapsulated pyrethrum and sesame oil and Novaluron.

(119) Formulation 7: Encapsulated tea tree oil.

(120) Formulation 8: Encapsulated tea tree and Novaluron with non-encapsulated pyrethrum and sesame oil.

(121) Formulation 9: Pyrethrum Citronella oil Sesame oil encapsulated in Lauric acid with CaCl.sub.2.

(122) Formulation 10: Encapsulated tea tree and Novaluron with non-encapsulated pyrethrum and sesame oil and Novaluron.

(123) Formulation 11: Tea tree oil encapsulated in Lauric acid by CaCl.sub.2 with non-encapsulated Pyrethrum and Sesame oil.

(124) Formulation 12: Tea tree oil encapsulated in Lauric acid by CaCl.sub.2 with non-encapsulated Pyrethrum and Sesame oil.

(125) Formulation 13: Citronella oil encapsulated in stearic acid by CaCl.sub.2 with non-encapsulated Pyrethrum and Sesame oil.

(126) Formulation 14: Tea tree oil encapsulated in stearic acid by CaCl.sub.2 with free Pyrethrum and Sesame oil.

(127) Formulation 15: Citronella oil encapsulated in decanoic acid by CaCl.sub.2 with non-encapsulated Pyrethrum and Sesame oil.

(128) Formulation 16: Tea tree oil encapsulated in decanoic acid by CaCl.sub.2 with non-encapsulated Pyrethrum and Sesame oil.

(129) Formulation 17: Citronella oil encapsulated in decanoic acid by MgCl.sub.2 with free Pyrethrum and Sesame oil.

(130) Formulation 18: Tea tree oil encapsulated in decanoic acid by MgCl.sub.2 with free Pyrethrum and Sesame oil.

(131) Formulation 19: Each of the above formulations was also encapsulated using fatty acids with divalent Ca or Mg salts, such as Ca(OH).sub.2 or Mg(OH).sub.2 or with a variety of other divalent or trivalent ions with varying counter ions.

B) Repellency Tests

Example 1

(132) A cocktail of three essential oils of active ingredients such as citronella, lavender and geranium in a ratio of 1:1:1 dissolved in almond oil to form a 24% solution of active ingredients may be prepared in lab or purchased as a solution under the trade name Di-Tush (Tamar LTD, Israel).

(133) In this example, 153 g of Di-Tush with an active essential oil concentration of 24% was mixed with 19.8 g of TDI and dispersed in an aqueous solution of 270 g water, and 2.7 g PVA. About 5 minutes after the microcapsules were formed 32.3 g of PEG 4000 dissolved in 75 g of water were added and the mixing was continued. At the end of the preparation 2.4 g Nefocide, 0.7 g Rodopol and enough Sodium biphosphate to bring the pH level to about 6 were added.

(134) Formulation 1 with a 48% active concentration was also prepared in a similar fashion. Both formulations showed good mosquito repellent properties when sprayed on floors and wall. Both formulations showed a longer duration of activity than the non-encapsulated formulations.

Example 2

(135) A solution of 35 g TDI mixed into 250 g of Formulation 1 having 6% active ingredient was added into 500 g water containing 5 g PVA using a high sheer mixer. To this were added 120 ml of water with 55.6 g PEG 4000. The mixing was continued for two hours at room temperature. To this dispersant were added 12 g Guar gum and 4 g of a fungicide (Nefocide). To break up the hydrogel, 10 g SDS (1%) was added.

(136) When sprayed over half an acre area at a concentration of 50 ml to 1,000 ml of a 0.05 to 1% or at a 0.1% to 0.5% concentration over 1 acre of land in a neighborhood of residential homes it kept that area free of mosquitoes for 2 weeks while the neighboring areas were heavily infested. This formulation showed a longer duration of activity than the non-encapsulated formulations of the same essential oils or commercial non-encapsulated essential oils.

Example 3

(137) 100 g Citronella oil with 12 g decanoic acid dissolved therein were added to a rapidly stirring (high speed shear stirrer) solution of 250 ml H.sub.2O with 2.5 g PVA. To this, a solution of 22.8 g hexahydrate MgCl.sub.2 in 20 ml H.sub.2O were added and stirred for two hours. Next, 20 g Pyrethrum, 2 g Sesame oil, 1.5 g methyl paraben, 8 ml Latron B 1956 and 3 g Guar gum were added with continual stirring for another 2 hours.

Example 4

(138) Example 3 was repeated but without the Pyrethrum. Both Formulations 3 and 4 showed good mosquito repellant properties when sprayed on surfaces such as home and office walls, floors, ceilings, furniture, nets, screens, lawns, clothing, car seats, surfaces in animal husbandries, and aquacultures.

Example 5

(139) Formulation 5 was prepared similarly to Formulation 1 using 93 g citronella oil, 10 g Pyrethrum and 1 g sesame oil instead of the Di-Tush product.

Example 6

(140) Formulation 6 was prepared similarly to Formulation 1 using geranium oil as the encapsulated volatile essential oil instead of the Di-Tush product.

Example 7

(141) Formulation 7 was prepared similarly to Formulation 1 using tea tree oil as the encapsulated volatile essential oil instead of the Di-Tush product.

Example 8

(142) Formulation 8 was prepared similarly to Formulation 1 using lavender oil or clove oil as the encapsulated volatile essential oils instead of the Di-Tush product.

Example 9

(143) Formulation 9 was prepared using the following ingredients and quantities in a process essentially identical to that disclosed for Formulation 1. Instead of the Di-Tush product, the following ingredients were used: 2.1 g PVA, 88 g ginger oil, 22 g cottonseed oil, 15.3 g TDI, 24.4 g PEG 4000, 1.8 g Nefocide and 0.5 g Rodopol.

Example 10

(144) A formulation was prepared as a repellent against the common house fly (Musca Domestica).

(145) 250 grams of Di-Tush with an active essential oil concentration of 96% was mixed with 35 g of TDI and was dispersed in an aqueous solution of 500 ml water, with 5.0 g PVA. About 5 minutes after the microcapsules were formed 55.6 g of PEG 4000 dissolved in 120 ml of water was added and the dispersion continued until a uniform solution was formed (about 30 minutes to 2 hours). At the end of the preparation 4.0 g Nefocide and 10 g SDS (sodium dodecyl sulfate) were added. As stirring was continued, 12 grams Guar gum was added with the stirring being continued to achieve a uniform solution.

(146) To determine the repellency of this formulation, about 400 laboratory-grown adult flies were used in every replica of the test. The flies were confined to a closed environment and the number of landed flies was counted on the sprayed and unsprayed paper sheets of the prepared formulation.

(147) As may be seen from Table 3 below for all replicas the number of flies that landed on the sprayed paper was much less than for the control. In addition, in replica 1 after 48 h about 35% mortality was observed. For replica 2 after 1 h about 65% mortality was observed and after 5 h about 91% mortality was observed. A mortality of the whole population was observed after 24 hours.

(148) TABLE-US-00003 TABLE 3 The repellent effect against house flies (Musca Domestica) of the formulation of Example 10. The number of landed flies on sprayed and unsprayed paper sheet replica 1 replica 2 replica 3 Exposure (h) formula control formula control formula control 0 h 0 31 0 24 0 9 0 h:15 min 0 36 1 14 0 27 0 h:30 min 0 30 0 15 0 21 0 h:45 min 1 42 1 9 0 24 1 h 0 34 0 11 1 8 1 h:15 min 0 40 0 9 0 6 1 h:30 min 2 51 0 6 0 8 1 h:45 min 3 43 0 3 0 8 2 h 2 64 0 2 1 12 2 h:15 min 1 50 0 2 0 9 2 h:30 min 0 56 0 3 0 7 2 h:45 min 1 78 0 2 0 5 3 h 2 43 0 4 0 8 3 h:15 min 5 64 0 1 1 9 3 h:30 min 9 58 1 3 1 8 3 h:45 min 6 72 1 1 2 9 4 h 2 116 1 0 0 11 4 h:15 min 4 96 1 1 0 10 4 h:30 min 4 82 1 2 0 12 4 h:45 min 9 115 2 2 0 6 5 h 15 83 1 5 0 5 5 h:15 min 13 70 0 2 1 5 5 h:30 min 26 78 0 2 1 5 5 h:45 min 16 69 0 2 0 3 6 h 16 54 0 1 0 3 24 h 17 68 after 1 h, after 5 h, 24 h:15 min 16 54 about 65% about 87% 24 h:30 min 13 51 mortality after mortality after 24 h, 24 h:45 min 14 56 5 h, about 100% mortality 25 h 8 44 91% mortality; 25 h:15 min 9 48 after 24 h, 25 h:30 min 8 36 100% mortality 25 h:45 min 11 43 26 h 17 54 26 h:15 min 15 38 26 h:30 min 15 41 26 h:45 min 17 39 27 h 8 34 27 h:15 min 23 29 27 h:30 min 20 44 27 h:45 min 28 41 28 h 39 38 28 h:15 min 41 49 28 h:30 min 54 52 28 h:45 min 37 48 29 h 36 46 29 h:15 min 34 33 29 h:30 min 41 35 29 h:45 min 48 48 30 h 39 41 48 h 34 32 48 h:15 min 40 36 after 48 h c. 35% mortality

Example 11

(149) An insecticide formulation was prepared against ants (Tapinoma simrothi) and cockroaches (Germanica Blatella). The formulation of is a combination of formulations A and B prepared as follows:

(150) Formulation A:

(151) 112.5 g of tea tree oil and 18.3 g pyrinex were mixed with 18.7 g TDI. This solution was dispersed in an aqueous solution of 250 ml water containing 2.5 g dissolved PVA (polyvinyl alcohol). To this, 65 ml water, with 4.2 g ethylene diamine and 3.7 g diethylene triamine was added and the dispersion continued. After additional stirring a uniform dispersion was obtained into which 1.7 g Nefocide and 6.0 grams guar gum were added and the stirring was continued. The solution was then neutralized to pH 7 with for an acid such as citric acid. Next, 5.15 g sesame oil and 51.5 g pyrethrum were added and stirring was continued until a uniform mixture was obtained again.

(152) Formulation B:

(153) 112.5 g of tea tree oil and 18.3 g pyrinex were mixed with 17.5 g of TDI which were dispersed in an aqueous solution of 250 ml water with 2.5 g dissolved PVA (polyvinyl alcohol). To this, 70 ml water with 23.3 g PEG 3350 was added and the dispersion mixing continued, after additional stirring, to form a uniform dispersion. Then, 2.0 g Nefocide, 5.0 g SDS and 6.0 g guar gum were added and stirring was continued. Finally, 5.15 g sesame oil and 51.5 g pyrethrum were added and stirring was continued until a uniform mixture was obtained.

(154) Formulations A and B were next mixed in a ratio of 40 g of A and 20 g of B. To test the efficacy of this formulation a confined space in which ants or cockroaches were placed was sprayed with the combination and the percent mortality was determined. The results are given in Table 4 below.

(155) TABLE-US-00004 TABLE 4 The efficacy of the combined formulation against ants (Tapinoma simrothi) and cockroaches (Germanica Blatella) Cockroaches (male) Ants 0.50% 1% 2% Control 0.50% 1% 2% Time 0 0 0 0 0 0 0 0 0 0 2 50 30 75 0 100 100 100 0 4 90 85 95 0 24 100 100 100 0 After 21 days 0 0 0 0 0 0 0 2 0 0 20 45 60 95 4 10 0 35 100 100 100 6 10 0 45 24 15 35 95 After 1 month 0 0 0 0 0 0 0 2 0 5 5 0 5 65 4 0 15 15 45 80 100 6 24 15 20 80 After 1.5 month 0 0 0 0 0 0 0 2 0 0 0 5 25 35 4 0 0 0 30 85 100 6 0 0 0 70 95 24 10 20 85 After 2 month 0 0 0 0 0 0 0 2 0 0 0 0 0 0 4 0 0 0 20 50 65 6 0 0 0 50 70 80 24 After 2.5 month 0 0 0 0 0 0 0 2 0 0 0 15 87 91 4 0 0 5 90 100 100 6 0 0 5 100 24 15 25 20 After 3 month 0 0 0 0 2 5 15 70 4 35 75 100 6 80 100 24

Example 12

(156) The formation of essential oil microcapsules employed in drip irrigation systems was achieved by both interfacial polymerization and the method of the invention.

(157) 17.5 g TDI were mixed into 125 g clove oil and then added into 250 g water containing 2.5 g PVA using high sheer mixer. To this, were added 70 ml of water with 27.8 g PEG 4000. The mixing was continued for two hours at room temperature to afford a dispersant. To this dispersant were added 0.4 g of a xanthane gum (rodopol) and 2 g of a fungicide (Nefocide). To break up the hydrogel character of this emulsion, 5 g SDS (sodium dodecyl sulfate, 1%) was added.

(158) When this formulation was fed into the water input for either subsurface drip irrigation systems or above ground drip irrigation systems ground, it was found to control effectively both bacteria and fungal growth in the tubing and orifices of the system.

Example 13

(159) When the encapsulated essential oil of Example 1 was formulated together with herbicidal agents chosen from 2,6 dichlorobenzonitrile (Dichlobenil) and sodium methyldithiocarbamate (Metam), diquat and Paraquat, root growth into the water orifices was also effectively controlled as well as bacteria and fungal growth.

Example 14

(160) Example 12 was repeated using 125 g thyme oil instead of clove oil with the same good results in controlling effectively both bacteria and fungal growth in the tubing and orifices of the irrigation systems.

Example 15

(161) Example 12 was repeated using an essential oil having both antimicrobial and herbicidal activity, such as pine oil, tea tree oil or eucalyptus oil. Formulations comprising, each one or a combination of these essential oils showed good results in controlling effectively both bacteria and fungal growth in the tubing and orifices of the irrigation systems.

(162) In another aspect of the invention, the formulation may be incorporated into wrapping or containing materials such as those used to contain or hold articles of various materials, fruits or vegetables or any other body which may be attacked by such insects. The wrapping or containing materials may be designed such as to allow slow or controlled release of the essential oils from the wrapper or the container to the articles contained therein during storage or shipment. The wrapping or containing materials may for example be pouches, plastic or paper bags, nylon sheets, polyester sheets, paper wrapping, plastic or other sealed containers, paper or plastic materials for hand or machine wrappings of fruits and vegetables, and the like.

(163) Fruits and vegetables are characterized by high water content. Minimal water content is needed for it to remain useable product. Thus, drying out of fruits and vegetables has two effects: (1) it reduces the weight of the product and hence its value and (2) changes the chemical concentrations nutrients in the fruit or vegetable, a result that can enhance spoilage and at a minimum its taste. In all cases this is a considerable economic loss either to the seller or customer. Thus, there arises the need for a formulation which may form a coating around the fruit or vegetable, thereby reducing water evaporation and loss of nutrients. Use of such formulation may have a significant effect in maintaining the fruit or vegetable shelf life and time to market place.

(164) Additionally, it is known that post-harvested fruits and vegetables are labile to attack by such microorganisms and insects which penetrate their skin for a variety of reasons. The formulations employed in this aspect of the invention were found useful in protecting post-harvested fruits and vegetables from such attacks by forming thereon a barrier which is capable of repelling the microorganisms and insects.

(165) Thus, there is provided a film forming formulation which is capable of forming a coating on post-harvest fruits and vegetables. Both the film formed upon application and the essential oil contained within the microcapsules, or each of them independently prevent and control the attack by microorganisms and insects by first providing a physical shield and second by providing a long-term insecticidal or anti-microorganism protection.

(166) After application, the fruits and vegetables that have been covered by the formulation are allowed to dry, thereby allowing the physical barrier and prophylactic shield to form.

(167) The formulations used with this application comprise encapsulated essential oils which may be carried in an aqueous medium with other agents such as polymers and surfactants, present therein in order to stabilize the suspension.

(168) In one preferred embodiment, the formulation further comprises coating agents, which may or may not be identical to the polymers which stabilize the suspension, and which may form a protected coating on the sprayed substrate, i.e. fruit or vegetable.

Example 16

(169) A solution of 35 g TDI mixed into 250 g of tea tree oil was added into 500 g water containing 5 g PVA using a high sheer mixer. To this is added 120 ml of water with 55.6 g PEG 4000. The mixing was continued for two hours at room temperature. To this dispersant were added 12 g Guar gum and 4 g of a fungicide (Nefocide). To break up the hydrogel character of this emulsion, 10 g SDS (sodium dodecyl sulfate, 1%) was added.

(170) This formulation herein labeled N262 was tested on onions, carrots and potatoes against control (untreated) and others commercial formulations by the names HPP, Oxyfor, Shemer in two parameters: Lost of Weight and Rotting, as detailed in Tables 5 and 6 below.

(171) TABLE-US-00005 TABLE 5 Post harvest Red and Brown Onions Lost of Weight Tests (%) Red Onion Brown Onion 4 3 2 1 4 3 2 1 months months months month Treatment months months months month 24.6 9.1 4.5 3.2 Control 16.9 12.5 5.8 3.3 15.6 9.3 6.3 4.5 HPP 9.4 7.2 4.3 3.1 22.8 12.3 5.5 2.8 Oxyfor 20.6 9.3 4.1 2.7 30.7 15.5 6.5 3.5 Shemer 13.3 8.8 4.3 2.7 16.5 8.6 4.2 2.3 N262 11.5 8.1 5 3.6

(172) TABLE-US-00006 TABLE 6 Post harvest Red and Brown Onions Rotting Tests (%) Red Onion Brown Onion 4 month Treatment 4 months 22 Control 20 19.7 HPP 10.3 21.1 Oxyfor 13.7 27.1 Shemer 10 12.1 N262 12.3

(173) Additional experiments were carried out to determine the effect of formulation N262 on the decaying of stored carrots. The experiment was conducted with carrots grown in Kibbutz Alumim. The carrots were dipped in the different solutions for 30 seconds, stored for 1 month in a storage room at a temperature of 0-1 C. and for a further 6-day shelf life period at 25 C..

(174) The treatment of carrots followed the next procedure: Several groups of carrots were used:

(175) 1. Control groupuntreated carrots (labeled C);

(176) 2. Treated groupcarrots dipped in a suspension of pathogens: Sclerotinia sclerotiorum, Alternaria alternate, A. radicina (labeled T);

(177) 3. Commercial wash groupcarrots dipped in a solution of 150 ppm chlorine+0.2% iprodione (labeled Com);

(178) 4. Treated group IIcarrots having been treated as in group 2, and thereafter with the commercial wash as with group 3 (labeled Com+T);

(179) 5. N262 groupcarrots dipped in a 2% solution of N262 (labeled EO1);

(180) 6. Treated group III carrots treated as in group 2, and thereafter dipped in a 2% solution of N262 (labeled EO1+T);

(181) 7. N262 group II carrots dipped in a 4% solution of N262 (labeled EO2);

(182) 8. Treated group IV carrots treated as in group 2 and thereafter dipped in a 4% solution of N262 (labeled EO2+T);

(183) 9. N262 group III carrots dipped in a 6.6% solution of N262 (labeled EO3); and

(184) 10. Treated group V carrots treated as in group 2 and thereafter dipped in a 6.6% solution of N262 (labeled EO3+T).

(185) The results are shown in Table 7 below. It may be concluded that formulation N262 at a concentration of 2% reduces the inoculation of carrots more than the other treatments and may be used as a replacement of commercial wash (if the goal is to replace the chemicals by friendly materials).

(186) TABLE-US-00007 TABLE 7 Results of N262 on both fungal and bacterial decay of carrots exposed pathogens Sclerotinia sclerotiorum, Alternaria alternate, and A. radicina. Decay Decay-total Decay caused caused by (%) Decay-mix (%) by bacteria (%) fungi (%) Treatments 4.5 1.4 3.1 0 C 57 0 0 57 T 2.4 2.4 0 0 Com 11.9 2.8 0.3 8.8 Com + T 2.65 0.7 2.0 0 EO1 21.3 2.3 19 0 EO1 + T 9.6 5.8 3.8 0 EO2 31.2 1.0 4.2 26 EO2 + T 3.3 2.0 1.3 0 EO3 72.3 0.3 0 72 EO3 + T

(187) Additional experiments were carried out to determine the effect of formulation N262 on the decaying of stored sweet potatoes against Resopous and other rotting. The experiment was done with sweet potatoes by Agronomia Agriculture Company. The sweet potatoes were dipped in the different solutions for few seconds, and stored one month in a storage room at a temperature of 0-4 C..

(188) The treatment of sweet potatoes followed the next procedure: Several groups of carrots were used:

(189) 1. Control groupuntreated sweet potatoes (labeled C);

(190) 2. Treated groupsweet potatoes dipped in water (labeled W);

(191) 3. Treated group Isweet potatoes having been treated by 0.5% of BotanoCap formulation called B262 as in group 2 (labeled B1); and

(192) 4. Treated group IIsweet potatoes having been treated by 3.0% of BotanoCap formulation called B262 as in group 2 (labeled B2); and thereafter with the commercial formulation by the name of Magnet (Imazalil) as with groups 3 and 4 (labeled M).

(193) The results are shown in Table 8 below. It may be concluded that formulation B262 at a concentration of 0.5% and 3% reduces the inoculation of sweet potatoes more than the other treatments and may be used as a replacement to commercial wash against Resopous, especially if the goal is to replace the chemicals by friendly materials.

(194) TABLE-US-00008 TABLE 8 Results of B262 on both Resopous and other causes decay of sweet potatoes in storage room. Rotting by Resopous and other causes after one month (%) Treatments 16.48 C 17.45 W 10.98 B1 12.33 B2 20.81 M

Post Harvest Solid Formulations

Example 17

(195) A solid core formulation containing 64% tea tree was prepared as follows:

(196) First, the following solutions and components were prepared:

(197) A) 70 grams Aerosil A 300 were weighed.

(198) B) 22.8 grams of toluene diisocyanate (TDI) were weighed and dissolved into 181.2 grams of tea tree oil.

(199) C) A solution was prepared by mixing 5.4 grams of ethane diamine (EDA) and 4.7 grams of diethylene triamine (DETA) in 10.6 grams water.

(200) Preparation of Final Formulation:

(201) 70 grams Aerosil A 200 were placed in a rotating multiplex production drum (6005/mum MultiplexApex Construction LTD London). The TDI dissolved in the tea tree oil was added thereto and this solution was uniformly absorbed into the Aerosil A 300 powder. The tea tree/TDI solution was added in one step into the drum and the drum was rotated for 60 minutes to obtain a uniform distribution of powder. The aqueous solution of EDA/DETA was then sprayed into the drum, which was rotated for additional 2 hours.

(202) The above formulation, when checked for antibacterial and antifungal activity, gave excellent results and when applied as a powder on the carrots or within the container of post harvest carrots prevented bacterial and fungal infestations as compared to the control.

(203) The same reaction was repeated, substituting the TDI of Fluka with Voronate 220.

(204) The microcapsule powder was also formulated in an aqueous carrier and applied to the carrots with equally good results.

Example 18

(205) Example 17 was repeated using Oregano oil instead of tea tree oil to give a solid particle formulation containing 64% oregano. This formulation, when checked for antibacterial and antifungal activity, gave excellent results and when used on post harvest potatoes and prevented bacterial and fungal infestations as compared to the control.

Example 19

(206) Example 17 was repeated using a mixture of tea tree and oregano oil (in a ratio of 1:1) to give a solid particle formulation having 32% tea tree and 32% oregano. This formulation, when checked for antibacterial and antifungal activity, gave excellent results and when used on post harvest potatoes prevented bacterial and fungal infestations as compared to the control.

Example 20

(207) Decanoic acid (12 grams) was dissolved in tea tree oil (100 grams) and this solution was added to a rotating drum containing 70 grams Aerosil A 200, and rotated for 60 minutes at a speed that gives a uniform distribution. After this time, a solution containing 3.5 grams NaOH and 7 grams CaCl.sub.2 in 100 ml of water, was sprayed into the rotating drum and rotated for an additional two hours. The final microcapsules were found to have good antibacterial activity.

(208) Food Additives for Human and Animal Consumption

(209) Background

(210) The food industry makes use of unsaturated fatty acids in a variety of products suitable for the consumption of animals such as mice, rats, cows or cattle, horses, sheep, goats, and primates, including apes, chimpanzees, orangutans, fish, shellfish, crustaceans, birds (e.g., chickens, roosters, etc.), humans or domesticated animals (e.g., dogs and cats). Such fatty acids could for example, be eicosapentaneoic acid (EPA), docosahexaenoic acid (DHA), aracadonoic acid (ARA), and conjugated linoleic acid and linolenic acid (CLA). These unsaturated fatty acids exhibit characteristics which may affect their processing, manufacturing, storage, odor, compatibility and oxidation.

(211) Encapsulation of these fatty acids may solve some of these problems and make them suitable for direct consumption or incorporation in food products. Other food ingredients, such as vitamins, nutritional supplements, minerals, herbal products, food additives, amino acids, and the like, including, for example, beta-carotene, lutein, zeazanthin, iron salts, copper salts, selenium salts, flavonoids, co-enzyme Q10, herbs, spices, flavorants and extracts (such as allicin or garlic extract), are also candidates for encapsulation.

(212) Summary

(213) The encapsulated essential oil formulations employed are based on the encapsulating membranes and essential oils which are GRASS and/or FDA approved. In fact, all agents contained in the microcapsules or the formulations comprising them, are non-toxic to both humans and animals. Such formulations have been prepared using fatty acids or alkanoic acids as disclosed hereinabove. In brief, the acids are dissolved in the essential oil, and then emulsified in an aqueous solution. The acids are next crosslinked by multivalent cations such as Ca or Mg or Fe or other multivalent cations dissolved within the aqueous solution.

(214) More specifically, this method comprising:

(215) (a) admixing at least one alkanoic acid with at least one essential oil;

(216) (b) admixing the mixture of step (a) with an aqueous basic solution to obtain a suspension; and

(217) (c) admixing into the suspension of step (b) an aqueous salt solution comprising at least one multivalent cation, thereby obtaining an aqueous suspension of microcapsules of microencapsulated essential oil.

(218) In one embodiment, the method further comprises the step of filtering and collecting the wax or solid particles.

(219) In another embodiment, the particles are not separated from the liquid carrier and the formulation is used as is.

(220) When separating the solid microcapsules from the aqueous media, small amounts of essential oils may remain unencapsulated. In order to obtain oil-dry microcapsules, an absorbent capable of absorbing the excess oil is added, typically in small amounts. The absorbent may be selected amongst, for example, Celluloses, starch powders or Aerosil silicas such Aerosil 200 or 300, commercially available from Degussa. In some applications the Aerosil is the preferred absorbent.

(221) The invention further provides a method for preparing a microcapsule formulation containing a plurality of edible microcapsules, each having a core containing at least one essential oil and an outer shell surrounding said core, said method comprising:

(222) (a) admixing at least one alkanoic acid with at least one essential oil;

(223) (b) admixing the mixture of step (a) with an aqueous basic solution to obtain a suspension; and

(224) (c) admixing into the suspension of step (b) an aqueous salt solution comprising at least one multivalent cation, thereby obtaining an aqueous suspension of microcapsules of microencapsulated essential oil.

(225) In one embodiment, the core containing at least one essential oil further comprises at least one additive, said additive being preferably a food enhancing additive.

(226) In another embodiment of the invention, additives are added to the formulation before step (c). The additive may be in a solid form or a liquid form or a suspension of two or more such agents. Such additives may be selected from active pharmaceutical agents, natural or synthetic antioxidants, food supplements, vitamins, colorants, odorants, oils, fats, flavors, nonvolatile natural essential oils or other dispersants or emulsifiers. In some specific embodiments, the additives may be selected from gamma-linolenic acids, citrus oils such as orange oils, nutritional supplements such as Vitamin A, Vitamin E, Vitamin C, and Vitamin D, tocopherols, tocotrienols, phytosterols, Vitamin K, beta-carotene, marine oils, and omega-3 fatty acids, CoQ.sub.10, lipid soluble derivatives of more polar antioxidants, e.g. ascobyl fatty acid esters, plant extracts (e.g., rosemary, sage and oregano oils), algal extracts, and synthetic antioxidants (e.g., BHT, TBHQ, ethoxyquin, alkyl gallates, hydroquinones, tocotrienols).

(227) Specific examples of oils which may be added include, but are not limited to, animal oils (e.g., fish oil, marine mammal oil, etc.), vegetable oils (e.g., canola or rapeseed), mineral oils, derivatives thereof or mixtures thereof.

(228) The additive may be a purified or partially purified oily substance such as a fatty acid, a triglyceride or ester thereof, or a mixture thereof.

(229) In another embodiment, the additive is at least one carotenoid (e.g., lycopene), a satiety agent, a flavor compound, a drug (e.g., a water insoluble drug), a particulate, an agricultural chemical (e.g., herbicides, insecticides, fertilizers), or an aquaculture ingredient (e.g., feed, pigment).

(230) Specific examples of suitable fish oils include, but are not limited to, Atlantic fish oils, Pacific fish oils, Mediterranean fish oils, light pressed fish oil, alkaline treated fish oil, heat treated fish oil, light and heavy brown fish oil, tuna oil, sea bass oil, halibut oil, spearfish oil, barracuda oil, cod oil, menhaden oil, sardine oil, anchovy oil, capelin oil, Atlantic cod oil, Atlantic herring oil, Atlantic mackerel oil, Atlantic menhaden oil, salmonids oil, shark oil, and the like.

(231) Once the oil or water immiscible liquid is converted into a solid or wax type particle it may be filtered to recover the solids in the suspension or the suspension may be used as is.

(232) When there is a need to preserve the encapsulated oils prior to use, formulation adjuvants may be added to the formulation. These improve suspension stability and the ease of application. Such formulation adjuvants may be selected from but are not limited to density balancing agents, surfactants, thickeners, biocides, dispersants, antifreeze agents, salts and any combination thereof. The formulation adjuvants may be added to the encapsulated oils at a concentration of about 0.01% to about 30% by weight of the encapsulated oil product.

(233) The method of the invention may be used for the conversion of liquids to free-flowing powders or compressed solids, which can be used as components in the manufacturing of a final product, to store a substance, to separate reactive substances, to reduce toxicity of a substance, to protect a substance against oxidation, to deliver a substance to a specified environment and/or to control the rate of release of a substance.

(234) In another preferred embodiment of the invention, the encapsulated solid particles can be used for delivering any of the loaded substances described herein to a subject, which may include mammals such as mice, rats, cows or cattle, horses, sheep, goats, and primates, including apes, chimpanzees, orangutans, fish, shellfish, crustaceans, birds (e.g., chickens, roosters, etc.), humans or domesticated animals (e.g., dogs and cats).

(235) As disclosed hereinabove, the alkanoic acids employed in the method of the invention are preferably selected amongst those having melting point temperatures higher than 25 C. Additionally, the alkanoic acids are preferably 10 to 45 carbon in length.

(236) Examples of such acids which are suitable for this application are unsaturated acids selected from but not limited to 11-octadecenoic acid or 5,8,11,14-eicosatetraenoic acid, and omega-3 fatty acid. Examples of omega-3 fatty acids include, but are not limited to, -linolenic acid (18:3-omega-3), octadecatetraenoic acid (18:4-omega-3), eicosapentaenoic acid (20:5-omega-3) (EPA), docosahexaenoic acid (22:6-omega-3) (DHA), docosapentaenoic acid (22:5-omega-3) (DPA), eicosatetraenoic acid (20:4-omega-3), uncosapentaenoic acid (21:5-omega-3), docosapentaenoic acid (22:5-omega-3) including any derivatives thereof and any combinations thereof.

(237) Possible derivatives of omega-3 fatty acids may include esters derivatives, branched or unbranched C.sub.1-C.sub.30 alkyl esters, branched or unbranched C.sub.2-C.sub.30 alkenyl esters, or branched or unbranched C.sub.3-C.sub.30 cycloalkyl esters such as phytosterol esters and C1-C6 alkyl esters.

(238) The fatty acids may be extracted from natural sources including, however not limited to, aquatic organisms (e.g., anchovies, capelin, Atlantic cod, Atlantic herring, Atlantic mackerel, Atlantic menhaden, salmonids, sardines, shark, tuna, etc) and plants (e.g., flax, vegetables, etc) and microorganisms (e.g., fungi and algae).

(239) The concentration of oils within a formulation may vary between 0.01 to 90% and preferably 60% or higher for applications needed to convert oils to solids or in the range of 25% for aqueous formulations such as encapsulated pyrethrum.

(240) In a preferred embodiment of the invention, the resultant encapsulated materials suitable for animal consumption are in the form of a dry, free-flowing powder. These materials have the advantage of achieving and maintaining consistently high active agent levels, and/or excellent oxidation resistance. The encapsulated material prepared with the present encapsulating agents consistently achieves and maintain a relatively high level of the active agent. The active agent may be present in an amount of from about 5 to 90% (wt/wt) based upon the encapsulated material. In another embodiment, the active agent is present in an amount ranging from about 15 to 60% (w/w). A high level of active agent is desirable to reduce the cost of producing the final product as encapsulating agents are often expensive. Further, some encapsulating agents may contribute adverse or undesirable properties to the final system and it is thus desirable to reduce the amount of encapsulating agent used.

(241) The introduction of certain agents in their encapsulated form also provides the means to overcome problems associated with insolubility or low solubility of the agent in the media. Thus, encapsulating the food additive, e.g., vitamins, affords a form of the additive which may be dissolved or dispersed into the foodstuff at a concentration which is homogenous and measurable.

(242) It is important not only to achieve a high level of active agent, but also to maintain it so as to enable a longer shelf life. To further increase oxidation resistance, an anti-oxidant and/or reducing agent may be added to the oil. The encapsulated material is stable when stored as a powder and releases the active agent upon exposure to moisture. The resultant encapsulated material may be used at any level desired, the amount being dependent upon the amount of active agent to be incorporated and the product in which it is to be used.

(243) In one embodiment in which the encapsulated materials are used in a food product, the encapsulated material is used in an amount of from about 0.01 to about 10% by weight of the food product and in another embodiment up to about 5% (w/w).

(244) The solid encapsulated particles of the invention may be used in foodstuffs. The term foodstuff as used herein refers to any article that can be consumed (e.g., eaten, drank, or ingested) by a subject human, animal or fish.

(245) In one embodiment, the solid encapsulated particles of the invention may be used as nutritional supplements to a foodstuff. In another embodiment of the invention, the foodstuff could be a baked good, a pasta, a meat product, a frozen dairy product, a milk product, a cheese product, an egg product, a condiment, a soup mix, a snack food, a nut product, a plant protein product, a hard candy, a soft candy, a poultry product, a processed fruit juice, a granulated sugar (e.g., white or brown), a sauce, a gravy, a syrup, a nutritional bar, a beverage, a dry beverage powder, a jam or jelly, a fish product, or pet companion food. In another aspect, the foodstuff is bread, tortillas, cereal, sausage, chicken, ice cream, yogurt, milk, salad dressing, rice bran, fruit juice, a dry beverage powder, rolls, cookies, crackers, fruit pies, or cakes.

(246) In another embodiment the solid encapsulated particles of the invention may be used in pharmaceutical formulations. Pharmaceutical formulations may also include additional carriers, as well as thickeners, diluents, buffers, preservatives, surface-active agents and other components. Pharmaceutical formulations may also include one or more additional active ingredients which may or may not be by themselves active pharmaceuticals such as antimicrobial agents, anti inflammatory agents, anesthetics, and the like.

(247) In a further embodiment of the invention, the solid encapsulated particles prepared by any one of the methods disclosed herein may be used in personal care products including antiperspirants, deodorants, soaps, fragrances, and cosmetics; hair care products, such as hair sprays, mousses, shampoos, cream rinses, and gels; paper products such as diapers, sanitary napkins, paper towels, tissues, toilet tissues; animal care products such as kitty litter; and household products such as carpet cleaners, and air fresheners.

(248) The fatty acid (e.g., decanoic, or stearic or palmitic carboxylic acids) added to the oil may act as a surfactant to form the dispersion of the oil in the aqueous medium. However ionic or non-ionic surfactant may be needed. Such surfactant may be added during manufacture of the microcapsules in order to facilitate or control the size of the microcapsules and/or may be added after the microcapsules are manufactured in order to break up a gel that results from the microencapsulation and afford a flowable non-gel formulation. One preferred surfactant is sodium dodecyl sulfate (SDS). It may preferably be added in concentrations of 0.1 to 10% and most preferably in concentrations of 0.5% to 5%.

(249) Other non-limiting examples of preferred additives in addition to surfactants are stearic barrier polymers, which help maintain particle separation, such as polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA) and poly(ethoxy)nonylphenol. In some cases it is desirable to adjust the pH of the finished microcapsule formulation as, for example, when the solution of finished microcapsule is combined with other pesticides. Conventional reagents for adjustment of acidity or alkalinity may be used, including for example, hydrochloric acid, citric acid, sodium hydroxide, sodium carbonate, and sodium bicarbonate. Additional stabilizes that may be added are alginates, Xanthan gums, carboxymethyl cellulose, sodium salt, Xanthan gum, Karya gum and Locust bean gum, and the like.

(250) PVP is available at various molecular weights in the range of from about 20,000 to about 90,000 and all these can be used, but PVP of about 40,000 MW is preferred. Poly(ethoxy)nonylphenol are available under the trade-mark Igepal, with various molecular weights depending on the length of the ethoxy chain. Poly(ethoxy)nonylphenol can be used but Igepal 630, indicating a molecular weight of about 630, is the preferred poly(ethoxy)nonylphenol. Other examples of surfactants include polyether block copolymers, such as Pluronic and Tetronic, polyoxyethylene adducts of fatty alcohols, such as Brij surfactants and esters of fatty acids, such as stearates, oleates, and the like. Examples of such fatty acids include sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, and the like. Examples of the alcohol portions of the fatty esters include glycerol, glucosyl and the like. Fatty esters are commercially available as Arlacel C.R surfactants. Surfactants vary in their surfactant properties, and the surfactant properties affect the size of the microcapsules formed. Other things being equal, use of PVP of 40,000 MW will give larger microcapsules than Igepal 630. The surfactant used, and also the degree and extent of agitation, affect the size of the microcapsules obtained. In general, they may be from about 1 to about 100 micron in size, depending upon the conditions used. Other surfactants to form dispersions and emulsifiers may also be used such as sodium, potassium, magnesium, and calcium or ammonium salts of lignin sulfonate.

(251) As stated hereinbefore, the encapsulated solid particles may be either recovered from the reaction mixture or re-suspended in said non-volatile vehicle or in a solution containing thereof. Alternatively, any medium, aqueous or otherwise, which comprises the microcapsules, may be treated without initial separation from the medium in which they are manufactured (water) with at least one non-volatile vehicle. In most cases said medium is water. In cases where separation is preferred, the collection of the microcapsules may be achieved, depending on their size, by centrifugation or filtration and washed with several portions of an appropriate solvent, e.g. distilled water, to remove free reactants from the surface.

(252) Additionally, these particles may be dispersed or suspended in said non-volatile liquid or solid vehicle. In some cases, said non-volatile vehicle is a particulate solid, e.g. powder, by which the dispersion is preferably done by admixing an effective amount of dry microcapsules with said vehicle. In some cases, said non-volatile vehicle is a liquid, by which the suspension is preferably prepared by mechanically stirring an effective amount of the microcapsules in said vehicle.

(253) There is, thus, also provided a method for preparing edible microcapsules, said method comprising:

(254) (a) admixing at least one alkanoic acid with at least one essential oil;

(255) (b) admixing the mixture of step (a) with an aqueous basic solution to obtain a suspension;

(256) (c) admixing into the suspension of step (b) an aqueous salt solution comprising at least one multivalent cation, and

(257) (d) collecting the microcapsules from the aqueous media, thereby obtaining microcapsules of at least one microencapsulated essential oil.

(258) These microcapsules may be added to food products (such as sausages, salamis and processed meats in general, cheeses of all types, etc) to prevent or delay spoilage or discoloration caused by microorganisms. The encapsulated essential oil formulations may also include food preservative agents including, but not limited to benzoic acid, sodium benzoate, and calcium propionate, methyl paraben, ethyl paraben, propyl paraben or butyl paraben.

(259) The preservative or food additive microcapsules may comprise between 0.01 to 5% or preferably 0.1% and 1% of essential oil and 0.1% benzoic acid or paraben. The ingredients may be added to the foodstuff separately or together as may be necessary. The encapsulated essential oil may be added at a level in which there is no affect on taste or smell, or it may be added at higher levels if the smell or taste of an essential oil is desired. In some cases the encapsulated essential oil additive or preservative is used such that the concentration of oil, derivative or active ingredient thereof is between 0.01% and 1% and the concentration of benzoic acid or paraben is from 0.01% to 1%.

(260) In one embodiment of the invention, the formulation comprises oil of fennel and methyl paraben wherein the oil of fennel is used at a concentration of 0.2% and the methyl paraben are used at a concentration of 0.1%.

(261) The essential oil formulation used as a food preservative may be effective against inhibiting many microorganisms such as, and without being limited thereto: Listeria monocytogenes; Salmonella enteriditis; Staphylococcus aureus and vancomycin-resistant Enterococcus.

(262) The essential oils may be chosen from those with antimicrobial and/or fungicidal properties as disclosed hereinbefore in reference to other applications. Examples of such oils which may be used are Tea tree oil, thyme oil, Clove oil, Eucalyptus oil and oregano oil, citronella oil, basil oil, oil of fennel and oil of anise. Thus, the microcapsules may be used as preservatives and disinfectants for the storage of fruits, vegetables and grains in confined spaces such as cargo ships, silos storage houses, barns, silos. When used in these applications it may be applied as a powder it may be distributed to the surfaces of container or confined area or it may be packaged in porous bags or bottles and placed strategically in containers or confined areas containing fruits, vegetables and grains for the purpose of disinfection and preservatives against microbial or fungal growth for example or insect infestation.

Example 1

(263) Decanoic acid (12 gr) was dissolved in tea tree oil (100 gr). The resulting solution was added to a rapidly stirring (high speed shear stirrer) solution of H.sub.2O 250 ml with PVA (2.5 gr). To this, hexahydrate MgCl.sub.2 (22.8 gr) dissolved in H.sub.2O (20 ml) was added and the solution was stirred for two hours, after which Guar gum (3 gr) was added with continual stirring for another 2 hours.

(264) When this formulation was added to sausages it prevented bacterial and fungal growth.

Example 2

(265) Example 1 was repeated, replacing the tea tree oil with 125 g clove oil. The resulting solution was added to both white and yellow cheese during their manufacture controlling effectively both bacteria and fungal growth.

Example 3

(266) Encapsulation of powder of cod liver oil was achieved as follows:

(267) Solution A was prepared by dissolving 25 gr. of Stearic acid in 75 gr. of Cod liver oil at 70-80 C.

(268) Solution B was prepared by adding a solution of 3.5 gr. NaOH in 30 ml of water to solution A while stirring for 10 min.

(269) Solution C was prepared by adding a solution of 7 gr. CaCl.sub.2.2H.sub.2O in 70 ml of water to a mixture of solutions A+B while stirring for 10 min.

(270) The reaction mixture was filtered through Buchner funnel and air-dried. 10 gr of the dried product was next mixed with 2.5 gr Aerosil 200 or 300 to absorb residual non-encapsulated oil. The final product contained 60% cod liver oil as the active ingredient.

(271) The encapsulated product had a fish odor. When the entire process of dissolution and encapsulation was carried out under a nitrogen atmosphere the product no longer had a fish odor.

Example 4

(272) Encapsulation of oil used in the manufacture of animal feed was prepared as follows:

(273) Solution A was prepared by dissolving 25 gr. of stearic acid in 75 gr of a vegetable oil at 60 C.

(274) Solution B was prepared by adding a solution of 3.5 gr NaOH in 30 ml of water to solution A with stirring at 60 C.

(275) Solution C was prepared by adding a solution of 7 gr CaCl.sub.2.2H.sub.2O in 70 ml of water to a mixture of solutions A+B with stirring for 10 min at 60 C.

(276) The reaction mixture was filtered through a Buchner funnel and air-dried at room temperature. 10 gr. of the dried material was mixed with 2.5 gr. Aerosil 200 or 300. The final product contained 60% of the vegetable oil as the active ingredient.

Example 5

(277) The encapsulation of Pyrethrum in stearic acid/Ca salt was achieved as follows:

(278) Solution A was prepared by dissolving 15 gr. of stearic acid in 50 gr. of pyrethrum at 60 C.

(279) Solution B was prepared by adding a solution of 2.1 gr. of NaOH in 20 ml of water to solution A while stirring for 10 min.

(280) Solution C was prepared by adding a solution of 4.2 gr. of CaCl.sub.2.2H.sub.2O in 40 ml of water to a mixture of solutions A and B with stirring for 10 min.

(281) Solution D was prepared by mixing a mixture of solutions A, B and C with a solution of 10 gr. SDS, 0.4 gr. of Irganox 1076, 0.4 gr. Tinuvin 770 and 850 ml of water. The reaction mixture was stirred with high sheer mixture for 30 min. The pH was adjusted to 7 using Citric acid. The reaction mixture was additionally stirred for 30 min, at which point 3.5 gr. Rodopol 24 was added with stirring for 30 min.